求教，这个自定义的C#类是如何工作的？

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

/// <summary>
/// 动画行为类，提供有关动画的行为
/// </summary>
public class AnimationAction

{
    //附加在敌人上的动画组件引用
    private Animation anim;

    /// <summary>
    /// 创建动画行为类
    /// </summary>
    /// <param name="anim"></param>
    public AnimationAction(Animation anim)
    {
        this.anim = anim;
    }

    /// <summary>
    /// 播放动画
    /// </summary>
    /// <param name="animName"></param>
    public void Play(string animName)
    {
        anim.CrossFade(animName);
        //.........
    }

    /// <summary>
    /// 判断指定动画是否在播放
    /// </summary>
    /// <param name="animName"></param>
    /// <returns></returns>
     public bool IsPlaying(string animName)
    {
        return anim.IsPlaying(animName);
    }

}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

/// <summary>
/// 敌人动画，定义需要播放的动画片段名称
/// </summary>
public class EnemyAnimation : MonoBehaviour
{
    public string runAnimName;

    public string attackAnimName;

    /// <summary>
    /// 闲置
    /// </summary>
    public string idleAnimName;



    public string deathAnimName;

    public AnimationAction action;

    private void Awake()
    {
        action = new AnimationAction(GetComponentInChildren<Animation>());
    }


}

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

/// <summary>
/// 敌人AI
/// </summary>
[RequireComponent(typeof(EnemyAnimation))]
[RequireComponent(typeof(EnemyMotor))]
[RequireComponent(typeof(EnemyStatusInfo))]

public class EnemyAI : MonoBehaviour
{
    //定义敌人状态
    public enum State
    {
        //攻击
        Attack ,
        //寻路
        PathFinding

    }
    /// <summary>
    /// 敌人当前状态
    /// </summary>
    private State currentState = State.PathFinding;
    private EnemyAnimation anim;
    private EnemyMotor motor;

    private void Start()
    {
        anim = GetComponent<EnemyAnimation>();
        motor = GetComponent<EnemyMotor>();

    }

    private float atkTimer;
    /// <summary>
    /// 攻击间隔
    /// </summary>
    public float atkInterval = 3;
    private void Update()
    {
        //判断
        switch (currentState)
        {
            case State.PathFinding:
                PathFinding();
                break;

            case State.Attack:
                Attack();
                break;
        }

        //寻路，攻击
    }

    private void PathFinding()
    {
        anim.action.Play(anim.runAnimName);
        //执行寻路 调用motor类中寻路方法，播放跑步动画
        //如果寻路结束，修改状态为攻击

        if (motor.Pathfinding() == false) currentState = State.Attack;
    }

    private void Attack()
    {
        if (anim.action.IsPlaying(anim.attackAnimName) == false)
            anim.action.Play(anim.idleAnimName);
            //如果动画没有播放
            if (atkTimer <= Time.time)
            {
                //进行攻击 播放攻击动画
                anim.action.Play(anim.attackAnimName);
                atkTimer = Time.time + atkInterval;
            }
    }

}